Digital Workshop

Just to ask if to use wmv video in Opus Pro 04 is as safe as mpg-1? Any detailed info or experience about? Is Opus Pro 05 Better than 04 in this area?

thanks

F

I've used both with equal success on newer, multimedia computers. WMV files tend to be smaller in my experience. They look/sound the same.

My concern with WMV files would be on older computers. I believe MPEG files might be more universally playable since the format has been around longer.

Hello Fred......Thanks for your promptly and useful answer. Can you let me know what is the minimum pc requirements for to use wmv, and if is possible use full window size with this codec?....If not what is the maximum size you recommend.... around 640 pixels wide will be fine?....more...less?

Thanks for your time.......

Federico

Federico --

Good to hear from you! You must have been on "holiday" because we haven't seen a post from you for awhile.

When I make an MPEG-1 video, I usually choose 320x240 pixels. There's a wider format (352x240) also possible. I just checked and WMV files default to 320x240 with no other option available in Pinnacle's Studio 9 video editing/DVD creation software.

On Windows XP machines with at least 128MB RAM I've run MPEG-1 files enlarged to 640x480 pixels. A client had an old computer with only 100MB RAM and it worked too. I had a client want 800x600 which runs OK, but it is so grainy (remember, the customer is ALWAYS right). I don't recommend going larger than 480 pixels wide. I've found the quality really starts to degrade above 480. Your results may vary depending on the computer, video card, and monitor/size. What looks OK on a 15" monitor may look terrible on a 21" monitor.

Low RAM Pentium 2 & 3 computers will really struggle to show videos, especially if you are asking them to enlarge the default format. I tend to try to go with the most common screen size, color depth, and default video sizes, along with .wav audio files, but there's always someone who's got hardware (usually OLD hardware) that won't work.

The guy was right when he said "...you can't please all the people all the time!"

I'd suggest being a little cautious when using WMV video files. And it depends on the encoding app. The MS WMV SDK is by far the best.
I've seen MWV files choke Opus a number of times.
One of the problems with the WMV (mpeg4) format is that it's not entirely compliant with the OS API particularly when ya need to know current location of playback head and other information such as FPS.
We still stick with mpeg1 (unfortunately).

Just more on frame size - mpeg1 frame size is generally 352x288 for pal and 352x240 for ntsc, stick with those as they are the most compliant. Strange figures I know but the numbers must be devisable by 8 to be compliant.
Also, WMV (mpeg4) doesn't have frame size restrictions. If we do use WMV we make them full frame 720x576 (pal) at a decent data rate of around 1.6m and the file size remains below that of mpeg1.

Correct me if I am wrong but Mpeg frame size can be any size there are guideline sizes but my understanding is these are aimed at Mpegs created specifically for play back on TV screens either as VCD or SVCD hence the different sizes for pal and NTSC. I have seen many publications were users have used larger Mpeg files without any problems. Unless you know the exact specifications of the machines your are publishing for I would be inclined to stick to Mpeg.


Regards

Brenden Knifton

Well, in the past I read some about the mpeg must has the same width and high relation: a exact multiple from 320 x 240 or 352 x 240....But I used sizes like ie: 352 x 180 or 400 x 200 without any problem...

By other side I made many times 720 x 480 and 704 x 480 mpeg-1 videos (from 720 x 480 miniDV) and it runs perfectly in pc's from around 1GB proccesor...And of course...it looks a lot better when compared with a 352 x 240 re-scaled to a big size......

But as you know when you need to make 1.000 or more cd's...the panic that it can fail or be choppy in clients pc's comes to home to live with me...hehehehehehe.....So I ever ask the same questions along the years.....

thanks

Again this may have more to do with TV playback were Aspect Ratio comes into play either 4:3 or 16.9. If your publication is being played back on a PC then as long as it fits the page you should be alright.

Regards

Brenden Knifton.

The following is taken form the mpeg-1 standard:

Good information but there are only a few places where the mpeg1 standard HAS to be addhered to. Making a video cd (mpeg1) to play in a standard set top dvd player you must have the exact mpeg1 specs or it will not play at all. For a computer, as many have found, the standard can be fudged quite a bit with no ill effect except possibly being too much for a computer to handle. That same computer would also not handle other formats with the same demands made on them. Mpeg 1 is still one of the best for maximum compatability, even with modified authoring.

I believe Brendon's statement to be the de-facto position here - the "standard" you are quoting was a guideline way back when mpeg1 was implemented, at that time a "fast" computer was 200MHz and there was no way that such a computer would be able to reliably playback frame sizes any bigger. While these numbers (352x288 and 352x240) are often quoted as the "standard", they are nowadays generally regarded as merely guidelines that have since been overtaken by computer developments.

A full size PAL frame is 720x576, and a full size NeverTheSameColour frame is 720x480 - both will play back fine as mpeg1 on any reasonably recent machine - if they don't (and assuming the encoding has been done properly) there are most likely other issues with that machine that need sorting. I have used 720x576 extensively for many years in productions (because it's very close to an 800x600 screen resolution) without any problems or complaints.

Many people seem to use the "standard" mpeg frame sizes and then rescale by doubling at playback time ...my own testing has shown that this usually places a heavier burden on a given PC/software combination that playing full frames out directly.

Rob Kirkwood
www.visibleform.co.uk

I am agree 100% with Rob opinion..... the Swan acotation was correct (and very useful) in the old days......Now you can use mpg-1 videos any size you want if you do it in a correct way.....

As far as I'm aware the standard hasn't changed since 1993 when it was published.
And my point was on encoding frame size not playback.